Dewatering machine



Sept. 18,1923. 1mm

H. B. CLEVELAND DEWATERING MACHINE Filed Oct. 1921 3 SheetsSheet 2 I -f \\\x\\\\\\\\\\\ r LIIHIIHII t an HENRY BURDETT CLEVELAND, OF '1 SGHODA H YQEK nnwa'rnnme moan.

' Application filed October 8, 1921. serial No. 506,388.

To all whom it may concern .Be it known that I, HENRY Bmmm'r CLEVELAND, a citizen of the United States, and resident of East Schodack, in the county of Rensselaer, and State of New York, have invented certain new and useful Improvements in Dewatering Machines; and I do hereby declare that the following is a full, clearfand'exact description thereof.

This invention pertains'to improvements in dewatering machines used in separatin bodies of difierent specific gravity, an more particularly to that type of centrifuge used in connection with activated sewage sludge or similar material in which the solid particles contained in the liquid are forced out by centrifugal force against the centrifugal wall ofthe centrifuge while the efiluent or liquid overflows at the top. At the present time there are two well known types of centrifuges employed namely, the solid wall and the perforated wall centrifuge. The solid wall centrifuge is only used' in connection with material in which thesolid particles are too minute to be retained in the drum by any perforated Wall or sieve which may be racti- 'cally used. The disadvantagezof the particular type of centrifuge resides in the fact thata certain amount of moisture is retained. within the cake or mass deposited a ainst the solid peripheral wall, which is o jectionable to the subsequent handling of the cake after it is discharged from the centrifuge.

The sieve or perforated wall centrifuge which, while very desirableby reason of a eater degree 9f separation efl'eeted,-ma employed only for materials in whic the solid particles are large enough to be retained within the drum by the perforated wall or sieve.

In order to use this particular type of centrifuge for material containing very fine particles of solid matter, it is necessary to provide small openings in the peripheral walland in operation it has been found that" this is impractical inasmuch as clogging of the openings results which interferes greatly with the operation of the centrifuge.

In view of the foregoing, it is the object of the present invention to combine the advantages of both types of centrifuge and at the same time eliminate the objectionable features by providing means for converting the centrifuge from asolid peripheral 'int wall to a sieve or perforated peripheral wall during the various stages of separation.

Incidental to the foregoing, a more specific object resides in the provision of a peripheral wall having perforations and means for axially moving the peripheral wall to bring the erforation in and out of gommunication with the separating chamer. 7

With the foregoing and other objects in view, the present invention consists in what is herein shown and described and more particularly pointed out and defined by the ap ended claims.

no form in which the present invention is embodiedis disclosed in the accompanyin% drawings in which,

1gure 1 1s a vertical sectional view through the invention.

Figure 1 is an enlarged detailed section taken through the perforations in the peripheral wall, and

Figures 2 and 3 are views similar to Figure 1, showing the peripheral wall in its various operative positions.

Referrin now more particularly to the accompanying drawings, the present invention is embodied in a machine of the general structure and operation disclosed in Patent No. 1,160,635, patented November 16, 1915, the main rotating parts being mounted upon a central shaft 1 which is' supported and rotated by suitable means not shown.

Secured to the shaft is a head 2 in which are disposed the pistons 3 actuated by fluid or hydraulic means similar to that employed e above noted patent. Carried by the head 2 and secured thereto, are a pair of spaced and walls comprising the bottom wall a and top wall 5 which are connected by the vertical ribs 6. A peripheral wall 7 engages the outer edges of the end walls a and 5 to form a separating chamber 8. Depending from the lower edge of the peripheral wall 7 is an annular plate 9 connected to the lower end of the pistons 3.

In order to obtain the proper joint between the peripheral wall 7 and the end walls 4 and 5 that will positively prevent the penetration of liquid, it has been found necessary to employ the gaskets 17 which are fitted into annular recesses 18 fod in the periphery of the end walls. These gaskets are so constructed and mounted that they are acted upon by centrifugal force and pressed outwardly against the interior of the peripheral wall '7.

In order that the gaskets may be subjected to the action of centrifugal force, it is obvious that they cannot be single rings but must be made up in sections. This brings up the problem of retaining the gasket in the recess 18 of the upper wall when the peripheral wall is lowered and I have provided for the same by slidably mounting an annular follower 19 on the periphery of the up er wall'5.

s shown in Figures 1 and 2, this follower is held into engagement with the upper edge of the peripheral wall 7 by means of a plurality of contractile springs 20.

When the peripheral wall 7 is lowered to the discharging position shown in Figure 3, the follower 19 is permitted to pass over the gasket disposed in thenpper wall, thereby serving to retain the same, within the annular recess 18.

As set forth in the foregoing objects, the present invention consists in converting the peripheral wall from a solid wall to a perforated wall during various stages of separation, and a simplified way of accomplishing this is the provision of an annular recess 10 on the inner surface of the peripheral wall 7. Fitted into this recess is an annular ring 11 provided with elongated slots or perforations 12. Communicating with the annular recess 10 and the lower edge of the peripheral wall, are a plurality of discharge passages 13.

Mounted on the shaft 1 above the head 2 is an auxiliary flared drum 14 having a peripheral wall terminating adjacent the bottom of the separating chamber and provided at its up or end with an annular pocket 15 adapte to receive the material fed to the machine. This pocket is connected with the interior of the drum by the communicating passages 16.

It will. be understood that while I prefer to use the auxiliary drum, the same forms no part of my present invention, but is described and claimed in my pending application filed May 23, 1921, Serial No. 71,796.

The operation of the invention is as follows:

Activated sludge or similar material, in which it is desired to separate the solid particles from the liquid, is fed into the annular pocket 15 of the auxiliary drum. the same being rotated at a high speed. The sludge then travels through the communicating passages and is held in contact with the peripheral wall of the auxiliary drum, which due to its flared shape, will cause the sludge to travel downward and be discharged at the lower end in a fine sheet that will be forced into contact with the peripheral wall 7 of the main drum. This takes place with the ei ipheral wall 7 in that position shown in igure 1.

The purpose of the auxiliary drum is to impart rotation to the sludge before it comes in contact with the main or separating drum, thereby insuring a maximum number of revolutions of the sludge as it travel upward from the lower portion of the drum..

Thematerial discharged from the auxiliary drum into the main drum is held against the peripheral wall by centrifugal force, causing the solid particles to be thrown out radially against the peripheral wall which will result in building up a cake or mass of the solid particles, while the effluent or liquid will travel upwardly and overflow through the central opening in the top wall. i

In operation of the centrifuge it has been found that the coarser or heavier solid particles are the first to be separated or forced from the liquid, and consequently these heavier particles come into contact with the peripheral wall at a point adjacent the bottom wall, as illustrated in Figure 2.

Because of the foregoing, the cake or mass built up at this point is more porous and gradually increases in density towards the upper part of the separating chamber. For this reason the perforations 12, which are provided in the peripheral wall, are positioned below the bottom wall during the initial separation of the solid particles from the liquid, and after the cake or mass is built up to a point where it has practically filled the annular separating chamber 8, the supply of sludge is shut off and the pistons 3 are actuated to axially move the peripheral wall to the position shown in Figure 2, bringing the perforations into communication with the separation chamber at that point where the cake or mass is most porous. At this stage, the supply of sludge having been shut off, all of the liquid separated from the solid particles has been discharged through the top wall, leaving a moist compact cake or mass in the separating chamber that contains a certain amount of liquid which, because of the continued rotation of the cake now in contact with that portion of the peripheral wall having the perforations, will be forced through-the cake and perforations into the annular passage 10, and discharged through the passages 13. The discharge passages 13 communicate with the lower edge of the peripheral wall in order to keep the liquid and subsequently discharged cake separated.

After the desired amount of liquid has been forced out of the cake, the peripheral wall, by, means of the fluid actuated pistons, is lowered to that position shown in Figure 3 to permit radial discharge of the cake or mass from the separating chamber. This discharged cake or mass has then reached the portion of dryness where it may be subsequently handled in the most practical way.

I claim:

1. A machine of the character described, having a separation chamber including a single peripheral wall provided withperforations and means for moving said peripheral wall axially to'bring the said perforations in and out of communication with the separation chamber and convert said wall from an imperforate wall to a perforated wall.

2. A machine of the character described, having a separation chamber including spaced end walls substantially rigid in respect to each other, and a single peripheral wall provided with perforations, and means for moving said peripheral wall axially to bring said perforations in and out of position between the end walls whereby said peripheral wall is converted from an imperforate wall to a perforated wall.

3. A machine of the character described including a separation chamber having spaced end walls and a single peripheral wall provided with perforations, and means for axially moving the peripheral wall to bring the perforations either above or below the bottom end wall whereby said peripheral wall is converted from an imperferate to a perforated wall.

4. A machine of the character described including a separation chamber having spaced end walls and a peripheral wall provided with perforations, and means for axially moving the peripheral wall whereby in its raised position the said perforations communicate with the separating chamber at a point adjacent the bottom end wall, while in the lowered position, said perforations are out of communication with the separating chamber.

5. A machine of the character described including an axially movable peripheral wall, spaced top and bottom walls having annular gaskets in their periphery seated against the inner surface of said peripheral wall and a follower slidably carried by the top wall and adapted to retain the gasket when the peripheral wall is lowered.

' 6. A machine of the character described including an axially movable eripheral wall, spaced top and bottom walls having annular gaskets in their periphery seated against the inner surface of said peripheral wall, and an annular follower slidable on the periphery of the top wall to retain the gasket when the peripheral wall is lowered.

7. A machine of the character described including an axially movable peripheral wall, spaced top and bottom walls having annular gaskets in their periphery seated against the inner surface of said peripheral wall, an annular follower slidable on the periphery of the top wall to retain the gasket when the peripheral wall is lowered, and springs for urging the follower in one direction.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of lVisconsin.

HENRY BURDETT CLEVELAND. 

